Image forming apparatus

Abstract

An image forming apparatus includes a photoconductor capable of bearing developer; a rotatable intermediate transfer member serving as an intermediate medium when transferring the developer on the photoconductor to a medium; a voltage supply section supplying to the intermediate transfer member a transfer voltage for letting the developer on the photoconductor advance to the intermediate transfer member at a primary transfer location; a secondary transfer member for transferring to the medium the developer that has moved to a secondary transfer location through rotation of the intermediate transfer member; a removal member arranged downstream from the secondary transfer location, with respect to a rotation direction of the intermediate transfer member, the removal member abutting against the intermediate transfer member and removing remaining developer remaining on the intermediate transfer member; and a controller that controls the voltage supply section, which does not cause the supply of the transfer voltage with the voltage supply section during the removal, with the removal member, of the remaining developer located upstream from the secondary transfer location, with respect to the rotation direction of the intermediate transfer member, and located between the primary transfer location and the secondary transfer location when a situation has arisen in which an image forming operation is stopped midway, in order to resume the image forming operation.

1. An image forming apparatus comprising:
 a photoconductor capable of bearing developer; 
 a rotatable intermediate transfer member serving as an intermediate medium when transferring the developer on the photoconductor to a medium; 
 a voltage supply section supplying to the intermediate transfer member a transfer voltage for letting the developer on the photoconductor advance to the intermediate transfer member at a primary transfer location; 
 a secondary transfer member for transferring to the medium the developer that has moved to a secondary transfer location through rotation of the intermediate transfer member; 
 a removal member arranged downstream from the secondary transfer location, with respect to a rotation direction of the intermediate transfer member, the removal member abutting against the intermediate transfer member and removing remaining developer remaining on the intermediate transfer member; and 
 a controller that controls the voltage supply section, which does not cause the supply of the transfer voltage with the voltage supply section during the removal, with the removal member, of the remaining developer located upstream from the secondary transfer location, with respect to the rotation direction of the intermediate transfer member, and located between the primary transfer location and the secondary transfer location when a situation has arisen in which an image forming operation is stopped midway, in order to resume the image forming operation, wherein 
 the voltage supply section is capable of supplying to the intermediate transfer member the transfer voltage for letting the developer advance to the intermediate transfer member and of supplying to the intermediate transfer member a reverse transfer voltage having a polarity opposite to a polarity of the transfer voltage for repelling the developer from the intermediate transfer member, and 
 the controller causes the supply of the reverse transfer voltage with the voltage supply section during the removal, with the removal member, of the remaining developer located upstream from the secondary transfer location, with respect to the rotation direction of the intermediate transfer member, and located between the primary transfer location and the secondary transfer location when said situation has arisen in which an image forming operation is stopped midway, in order to resume the image forming operation. 
 
   
   
     2. An image forming apparatus according to  claim 1 , wherein the voltage supply section supplies the transfer voltage across the entire intermediate transfer member. 
   
   
     3. An image forming apparatus according to  claim 2 
 wherein an electrode layer is arranged at an end portion of the intermediate transfer member in a perpendicular direction that is perpendicular to the rotation direction of the intermediate transfer member, 
 the image forming apparatus further includes a conductive member abutting the electrode layer, and 
 the voltage supply section supplies the transfer voltage via the conductive member to the intermediate transfer member. 
 
   
   
     4. An image forming apparatus according to  claim 1 ,
 comprising four photoconductors capable of bearing developer of four different colors, 
 wherein the intermediate transfer member serves as an intermediate medium when transferring the developer on each of these photoconductors to the medium. 
 
   
   
     5. An image forming apparatus comprising:
 a rotatable image bearing member for bearing a latent image; 
 a developing device for developing the latent image borne by the image bearing member with developer at a developing location; 
 a rotatable intermediate transfer member serving as an intermediate medium when transferring the develouer on the image bearing member to a medium; 
 a voltage supply section supplying to the intermediate transfer member a transfer voltage for letting the developer on the image bearing member advance to the intermediate transfer member at a primary transfer location; 
 a secondary transfer member for transferring to the medium the developer that has moved to a secondary transfer location through a rotation of the intermediate transfer member; 
 a removal member arranged downstream from the secondary transfer location, with respect to a rotation direction of the intermediate transfer member, the removal member removing remaining developer on the intermediate transfer member without being transferred by the secondary transfer member, by abutting against the intermediate transfer member, 
 the removal member removing remaining developer that has remained on the image bearing member and the intermediate transfer member when a situation has arisen in which an image forming operation is stopped midway, and that has been moved through the rotation of the image bearing member and the intermediate transfer member and has reached a developer removal location at which the remaining developer is removed by the removal member, in order to resume the image forming operation; and 
 a controller that controls the voltage supply section, the controller 
 causing the supply of the transfer voltage with the voltage supply section until the remaining developer located at the developing location when said situation has arisen has been moved through the rotation of the image bearing member and has reached the primary transfer location, and 
 stopping the supply of the transfer voltage with the voltage supply section after the remaining developer located at the developing location when said situation has arisen has reached the primary transfer location and before the remaining developer located at the secondary transfer location when said situation has arisen is moved to the developer removal location through the rotation of the intermediate transfer member and removed by the removal member, wherein 
 the voltage supply section is capable of supplying to the intermediate transfer member the transfer voltage for letting the developer advance to the intermediate transfer member and of supplying to the intermediate transfer member a reverse transfer voltage having a polarity opposite to a polarity of the transfer voltage for repelling the developer from the intermediate transfer member, and 
 the controller stops the supply of the transfer voltage with the voltage supply section and causes the supply of the reverse transfer voltage with the voltage supply section after remaining developer located at the developing location when said situation has arisen in which an image forming operation is stopped midway has reached the primary transfer location and before remaining developer located at the secondary transfer location when said situation has arisen is moved to the developer removal location through rotation of the intermediate transfer member and is removed by the removal member. 
 
   
   
     6. An image forming apparatus according to  claim 5 ,
 wherein the controller lets the voltage supply section maintain the stop of the supply of the transfer voltage until the remaining developer located at the developing location when said situation has arisen in which an image forming operation is stopped midway has been moved to the developer removal location through the rotation of the image bearing member and the intermediate transfer member and is removed by the removal member. 
 
   
   
     7. An image forming apparatus according to  claim 5 , wherein a length of the image bearing member, in its rotation direction, from the developing location to the primary transfer location is shorter than a length of the intermediate transfer member, in its rotation direction, from the secondary transfer location to the developer removal location. 
   
   
     8. An image forming apparatus according to  claim 5 ,
 comprising four of the rotatable image bearing members capable of bearing developer of different colors; 
 wherein the intermediate transfer member serves as an intermediate medium when transferring the developer on these image bearing members to a medium. 
 
   
   
     9. An image forming apparatus according to  claim 8 ,
 wherein the four rotatable image bearing members are provided along the rotation direction of the intermediate transfer member, and 
 the controller 
 causes the supply of the transfer voltage with the voltage supply section until the remaining developer located at the developing location corresponding to a first image bearing member of the four rotatable image bearing members, which is furthest removed from the secondary image location on the upstream side, with respect to the rotation direction, of the intermediate transfer member when said situation has arisen in which an image forming operation is stopped midway is moved through the rotation of the image bearing members and the intermediate transfer member and passes the primary transfer location corresponding to a second image bearing member of the four rotatable image bearing members, which is closest to the secondary image location on the upstream side, with respect to the rotation direction, of the intermediate transfer member, and 
 stops the supply of the transfer voltage with the voltage supply section after the remaining developer located at the developing location corresponding to the first image bearing member when said situation has arisen has passed the primary transfer location corresponding to the second image bearing member, and before the remaining developer located at the secondary transfer location when said situation has arisen is moved to the developer removal location through the rotation of the intermediate transfer member and removed with the removal member. 
 
   
   
     10. An image forming apparatus according to  claim 9 ,
 wherein a total of a length, in a rotation direction, of the first image bearing member from the developing location to the primary transfer location and a length, in the rotation direction, of the intermediate transfer member from the primary transfer location corresponding to the first image bearing member to the primary transfer location corresponding to the second image bearing member is shorter than a length, in the rotation direction, of the intermediate transfer member from the secondary transfer location to the developer removal location.